The European tour, now the DP World Tour for sponsorship reasons, said on Monday that players who opt to compete on the LIV circuit in 2027 will not be allowed to be members.
That has implications for LIV golfers who want to play the Ryder Cup.
Some of the world's leading players have been given conditional releases in recent seasons that meant they could compete on the European tour and LIV.
LIV abruptly lost its deep-pocketed Saudi investors this year and now intends to restructure and return in a new form.
"LIV is in such a state of flux that you know I think the DP World Tour have been more than accommodating to LIV players," six-time major champion McIlroy said in Delhi ahead of the DP World India Championship starting on Thursday.
"And as I said, the DP World Tour are well within their rights to change the rules and regulations.
"And you know, this is a way to protect their business and to make the tour as strong as possible."
McIlroy, who is a global ambassador for DP World, added: "So in a very short way, I would say it's now being clarified totally.
"If you are with the tour, you're with the tour."